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Apple maggot

Quick facts 

  • The most important insect pest of Minnesota-grown apples is the apple maggot (Rhagoletis pomonella).
  • Appears in early July and is active until September. Peak activity occurs from late July through early August.
  • Heavily infested fruit is distorted and inedible, but can be used for cider or animal feed.
  • There are nonchemical and chemical options for managing apple maggots.
Apple maggot adult female

How to identify apple maggot

The adult fly is 1/4 inch long, smaller than a common housefly.

  • It has dark markings on the clear wings and a conspicuous white spot where the thorax joins the abdomen.
  • Has three (male) or four (female) white stripes on the abdomen.

Life cycle of apple maggot

Adult apple maggots begin to emerge from the soil starting around July 1, continuing through most of the summer. 

  • Adult flies often leave and feed outside the orchard, in wooded or brushy areas.
  • They return to lay eggs just under the skin of apples.
  • Each female fly can lay hundreds of eggs.
  • Once eggs hatch, larvae feed for three to four weeks.
  • When apples drop to the ground, the larvae transform into pupae in the soil.
  • Pupae spend the winter underground, emerging as adults the following summer.
Apple maggot larva
Apple maggot adult

Damage caused by apple maggot

  • Apple maggot flies lay eggs in fruit and the fruit becomes pitted and misshapen.
  • Each "sting” or hole created by the female fly as she lays an egg, forms a tiny spot or dimple.
  • Pulp breaks down, discolors and starts to rot as a result of maggots (larvae) tunneling through the flesh.
  • Larvae are rarely seen.
Dents caused by apple maggot flies laying eggs
Inside of an apple with apple maggots

How to protect your trees from apple maggots

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Jeffrey Hahn, Extension entomologist; Michelle Grabowski, Extension educator; and Jill MacKenzie

Reviewed in 2018

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